JP4710420B2 - Liquid distribution device and liquid ejection device - Google Patents

Description

  The present invention relates to a liquid circulation device and a liquid ejection device.

  2. Description of the Related Art Inkjet printers (hereinafter referred to as “printers”) are widely known as liquid ejecting apparatuses that eject liquid onto a target. In this printer, a recording head (liquid ejecting head) is mounted on a reciprocating carriage, and printing is performed on a recording medium by ejecting ink (liquid) supplied to the recording head from nozzles formed on the recording head. It has come to give. In such a printer, a valve device (for example, a choke valve) is provided in the middle of an ink supply tube (or ink discharge tube) serving as an ink flow path (liquid flow path), and ink is supplied via the valve device. Is known to efficiently flow in the ink flow path from the upstream side to the downstream side (see, for example, Patent Document 1).

  FIG. 6 is a sectional view showing a choke valve which is a kind of such a valve device. As shown in FIG. 6, the choke valve 60 is made of a base material 62 in which a concave portion 61 is formed on one side surface, and a flexible material fixed so as to cover the concave portion 61 on one side surface of the base material 62. And a film 64. A supply port 65 is formed in the inner surface 63 of the recess 61 in the base material 62 for allowing ink supplied from the upstream ink cartridge side to flow into the recess 61. Further, a convex portion 66 is formed substantially at the center of the inner surface 63 of the concave portion 61 in the base material 62, and ink is discharged from the concave portion 61 toward the recording head side which is the downstream side at the tip of the convex portion 66. A discharge port 67 for opening is formed. A sealed pressure chamber (liquid receiving chamber) that constitutes a part of the ink flow path is defined by the inner surface 63 of the recess 61 and the back surface (surface on the recess 61 side) of the flexible portion 64a of the film 64. 68 is enclosed.

The choke valve 60 configured as described above is a closed valve in which the film 64 is indicated by a two-dot chain line because the flexible portion 64a is flexible based on the supply pressure of the ink flowing into the pressure chamber 68 from the supply port 65. It is comprised so that a state and the valve opening state shown as a continuous line may be switched.
JP 2001-38925 A

  However, when ink flows, not only ink but also bubbles may be mixed in the pressure chamber 68 of the choke valve 60. In particular, when the choke valve 60 is arranged vertically as shown in FIG. 6, the bubbles are concentrated above the pressure chamber 68, and these bubbles are moved downward to be discharged out of the pressure chamber 68. It was difficult to do. If the bubbles in the pressure chamber 68 are not discharged, even if it is a small bubble at first, a plurality of bubbles gather to form a large bubble. When the volume of the bubbles is increased, the bubbles are relatively easily discharged from the discharge port 67. When the bubbles are supplied to the recording head together with the ink during printing, dot dropout occurs and printing cannot be performed satisfactorily. It was.

  The present invention has been made in view of such circumstances, and its purpose is to leave bubbles in the liquid receiving chamber even if a liquid receiving chamber is provided in the middle of the liquid flow path. An object of the present invention is to provide a liquid circulation device and a liquid ejection device that can circulate a liquid satisfactorily.

In order to achieve the above object, a liquid circulation device according to the present invention includes a liquid receiving chamber provided in the middle of a liquid flow path and constituting a pressure chamber of a choke valve, and an upstream side of the liquid flow path in the liquid receiving chamber. A liquid introduction device that introduces the liquid from the liquid receiving chamber, and a liquid outlet device that guides the liquid from the liquid receiving chamber to the downstream side of the liquid flow path, the liquid receiving chamber comprising: An inner wall surface is formed so as to form a substantially arc shape that draws an involute curve in a cross-sectional shape along the vertical direction of the liquid receiving chamber, and the liquid introduction portion continuously draws an involute curve on the inner wall surface of the liquid receiving chamber. together are formed as, and is formed to have a tapered gradually toward the downstream portion of the connecting portion between the liquid receiving chamber from the upstream portion, wherein the tangential direction of the inner wall surface of the liquid receiving chamber It connected to the liquid receiving chamber so as to introduce the liquid into the upper portion of the body receiving chamber, the liquid deriving unit and the liquid from the substantially center position in the vertical direction of the liquid receiving chamber to the liquid receiving chamber After the liquid introduced into the liquid receiving chamber from the liquid introduction portion flows in a circular shape from above to below along the inner wall surface of the liquid receiving chamber, the liquid introduction portion is connected. It is configured to be derived.

  If there is a corner in the liquid receiving chamber provided in the middle of the liquid flow path, bubbles mixed in the liquid easily remain in the corner. In this regard, according to the above configuration, the liquid introduced from the liquid introduction portion into the liquid receiving chamber from the tangential direction of the inner wall surface of the liquid receiving chamber is liquid along the inner wall surface of the liquid receiving chamber formed in a substantially arc shape. Smoothly flows through the receiving room. Therefore, even if bubbles are mixed in the liquid introduced from the liquid introduction unit into the liquid receiving chamber, the bubbles flow along the inner wall surface of the liquid receiving chamber together with the liquid, and then are led out together with the liquid from the liquid outlet unit. The Therefore, even if the liquid receiving chamber is provided in the middle of the liquid flow path, the liquid can be circulated satisfactorily without leaving bubbles in the liquid receiving chamber. In addition, when replacing the liquid in the liquid channel with a liquid of another color, the liquid before replacement tends to remain in the corners of the liquid receiving chamber even after the replacement, but in the liquid circulation device of the present invention, the replacement is performed. It is possible to discharge and replace the previous liquid without leaving it.

In addition , the liquid introduced from the liquid introduction portion into the liquid receiving chamber flows in a spiral shape along the inner wall surface of the liquid receiving chamber formed so as to draw an involute curve, and then the liquid receiving chamber serving as the center of the spiral. It is led out satisfactorily through a liquid lead-out part provided at a substantially central position.

Further, the liquid introduction portion, the so continuously to the inner wall surface of the liquid receiving chamber is formed so as to draw the involute curve, as the introduction of liquid from the liquid introducing portion to the liquid receiving chamber can be smoothly performed And more preferably, the liquid can be promoted to flow in a spiral shape in the liquid receiving chamber.

In addition , since the liquid introduction part is formed so as to gradually taper from the upstream part toward the downstream part serving as a connection part with the liquid receiving chamber, the flow rate of the liquid flowing through the liquid introduction part However, it becomes faster at the connecting portion with the liquid receiving chamber, so that the liquid can be vigorously introduced into the liquid receiving chamber, and the flow velocity of the liquid flowing along the inner wall surface of the liquid receiving chamber can be increased. Therefore, the liquid can be circulated more favorably without leaving bubbles in the liquid receiving chamber.

Further, since the inner wall surface of the liquid receiving chamber has a substantially arc-shaped cross section along the vertical direction, it is particularly a case of a so-called vertical installation type in which bubbles tend to remain in the upper portion of the liquid receiving chamber. However, the liquid can be circulated satisfactorily without leaving bubbles in the liquid receiving chamber.

In the liquid circulation device of the present invention, the liquid receiving chamber has an inner bottom surface formed flat.
According to this configuration, for example, the volume of the liquid receiving chamber can be increased as compared with the case where the inner bottom surface is formed in a tapered shape, so that a sufficient amount of liquid can be secured, and the liquid receiving chamber is provided with the valve device. When the pressure chamber is configured, the responsiveness of the valve device can be improved.

A liquid ejecting apparatus according to an aspect of the invention includes a liquid ejecting head that ejects liquid and the liquid circulation device, and a liquid outlet portion in the liquid circulation device is connected to the liquid ejecting head.
According to this configuration, it is possible to efficiently discharge bubbles in the liquid flow path by promoting the flow of the liquid, so that stable liquid ejection can be performed.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, an ink jet printer (hereinafter referred to as “printer”) 10 as a liquid ejecting apparatus in the present embodiment includes a main body case 11 having a rectangular parallelepiped shape. A platen 12 is installed in the lower part of the main body case 11 along the longitudinal direction thereof. The platen 12 is a support table that supports paper as a target, and the paper fed mechanism discharges the paper fed from the paper feed tray from the paper discharge tray (not shown) to the outside of the main body case 11. It has become.

  Further, a guide shaft 13 is installed above the platen 12 in the main body case 11, and a carriage 14 is movably inserted and supported on the guide shaft 13. In addition, a carriage motor provided in the main body case 11 is connected to the carriage 14 via a timing belt (not shown) that is mounted on a pair of pulleys. Accordingly, the carriage 14 can be moved in the longitudinal direction of the printer 10 via the timing belt by driving the carriage motor while being guided by the guide shaft 13.

  A recording head 15 as a liquid ejecting head is provided on the lower surface of the carriage 14. A plurality of ejection nozzles (not shown) are formed on the lower surface side of the recording head 15, and piezoelectric elements (not shown) are arranged in the recording head 15 so as to individually correspond to the nozzles. . Then, by driving and controlling each piezoelectric element, ink (liquid) is ejected from each nozzle toward the paper that reaches the lower side of the recording head 15. In addition, a sub tank 16 (also referred to as a valve unit) that supplies ink to the recording head 15 is mounted on the carriage 14.

  In the main body case 11, cartridge holders 18 and 19 are fixedly arranged at the left and right positions outside the moving space area of the carriage 14. A plurality (three in this embodiment) of ink cartridges 21 (see FIG. 3) are detachably attached to the cartridge holders 18 and 19, respectively. In this respect, the printer 10 of the present embodiment is not a so-called on-carriage type printer in which the ink cartridge 21 moves with the carriage 14, but is configured as a so-called off-carriage type printer 10 in which the ink cartridge does not move on the printer 10. Yes. Each ink cartridge 21 contains an ink pack (not shown) filled with ink.

  Each of the ink cartridges 21 and the sub tanks 16 are provided by the number of ink colors (for example, black, yellow, magenta, cyan, light magenta, light cyan) (six in this embodiment), and the sub tanks 16 are provided with ink supply tubes 22 for each color. Are connected to the ink cartridges 21 of the respective colors. Each sub tank 16 temporarily stores the ink taken from the ink cartridge 21 and adjusts the stored ink to a predetermined pressure to supply the ink to the recording head.

  Further, in the main body case 11, pressure pumps 23 and 24 configured by bellows pumps or the like are provided above the cartridge holders 18 and 19, and positions on the platen 12 side of the cartridge holders 18 and 19. The first flow path forming body 25 and the second flow path forming body 26 as liquid circulation devices connected to the ink cartridges 21 are respectively supported. When the pressurizing pumps 23 and 24 are driven, the ink pack in the ink cartridge 21 to which the pressurized air is sent from the pressurizing pumps 23 and 24 is deformed so as to be crushed. The ink stored in the ink cartridge 21 is pressure-fed to the corresponding flow path forming bodies 25 and 26.

  The flow path forming bodies 25 and 26 include attachment parts 25a and 26a formed in a substantially rectangular flat plate, and an extension part extending from the upper end part of the attachment parts 25a and 26a to the center position in the main body case 11. 25b, 26b. The attachment portions 25a and 26a and the extension portions 25b and 26b are provided with three ink flow paths for supplying ink to the ink cartridge 21 side (see FIGS. 2 and 3, the first flow path 34, the second flow path 38, The third flow path 51) is formed as a liquid flow path, and the proximal end portion of the ink supply tube 22 is connected to the distal ends of the extending portions 25b and 26b. Six ink flow paths (not shown) are formed in the ink supply tube 22, and communicate with the ink flow paths 34, 38, 51 of the flow path forming bodies 25, 26, respectively. The detailed configuration of the flow path forming bodies 25 and 26 will be described in detail later together with the configuration of a plurality of (three in the present embodiment) choke valves 40 (valve devices) provided in the flow path forming bodies 25 and 26. Shall.

  The tip of the ink supply tube 22 is connected to the sub tank 16 on the carriage 14 through a connection member (not shown) in which six ink channels (not shown) are formed. Accordingly, the ink in the ink cartridge 21 is supplied to the corresponding ink flow paths (first flow path 34, first flow path) of the flow path forming bodies 25, 26 by the pressure of the pressurized air supplied from the pressure pumps 23, 24. 2 channels 38 and 3rd channels 51) are supplied to the corresponding nozzles of the recording head 15 via the ink channels of the ink supply tube 22, the ink channels of the connecting member, and the subtanks 16. .

  In the main body case 11, a cleaning mechanism 20 is provided at a position below the carriage 14 for discharging and discharging the thickened ink from the nozzles (not shown) of the recording head 15 as waste liquid. The cleaning mechanism 20 includes a cap 27 that can seal the nozzle forming surface of the recording head 15, a suction pump 29, and an ink discharge tube 28 that connects the cap 27 and the suction pump 29. Then, the suction pump 29 is driven in a state where the nozzle forming surface of the recording head 15 is sealed with the cap 27, whereby the waste ink is sucked from the nozzles in the recording head 15, and the ink is discharged from the cap 27 and the ink discharge. The liquid is discharged to a waste liquid tank (not shown) through the tube 28.

  Next, the 1st and 2nd flow path formation bodies 25 and 26 as a liquid distribution | circulation apparatus are demonstrated with reference to FIGS. In the following description, the upper side in FIGS. 2 to 5 is described as “upper”. In addition, the first and second flow path forming bodies 25 and 26 are different only in that the connection portion with the ink supply tube 22 and the ink flow paths are symmetrical, and the other configurations are the same. The first flow path forming body 25 will be described.

  The first flow path forming body 25 includes a base material 30 made of a synthetic resin and a film 31 made of a thermoplastic resin fixed to the front surface 30a and the back surface 30b of the base material 30. Moreover, the 1st flow path formation body 25 is provided with the attachment part 25a and the extension part 25b as mentioned above. The extension part 25b is formed to bend from the upper part of the attachment part 25a to the left side. The extension part 26b of the second flow path forming body 26 is formed so as to be bent to the right side from the attachment part 26a, and the first and second flow path forming bodies 25, 26 are aligned with each other as shown in FIG. When arranged in a shape, the ends of the extending portions 25b, 26b face each other at the center.

  The attachment portion 25a is formed in a square shape, and a plurality of (three in the present embodiment) through which tubes (not shown) for supplying pressurized air are inserted below the base material 30 corresponding to the attachment portion 25a. ) Through holes 32 are formed in a row in the horizontal direction. In addition, a plurality (three in this embodiment) of communication holes 33 communicating with ink needles (not shown) provided in the cartridge holder 18 are formed through the insertion holes 32, respectively. Further, in the attachment portion 25a, three first flow paths 34 (liquid introduction portions) continuous to the respective communication holes 33 are formed in a groove shape. Each of these first flow paths 34 is formed so as to extend toward the extending portion 25b formed continuously with the attachment portion 25a. The terminal end (downstream end) of the first flow path 34 stops near one end (the right end in FIG. 2) of the extending portion 25b.

  FIG. 4 is an enlarged view showing the vicinity of the end (downstream end) of the first flow path 34. As shown in FIG. 4, at the end of the first flow path 34, an ink receiving chamber 35 having a circular cross section as a liquid receiving chamber is formed continuously with the first flow path 34. In the present embodiment, the terminal portion 34 a of the first flow path 34 is connected to the ink receiving chamber 35 so as to introduce ink from the tangential direction of the inner wall surface 36 of the ink receiving chamber 35. A through hole 37 (liquid outlet) is formed in the center of the ink receiving chamber 35 so as to penetrate to the back surface 30b. That is, the first flow path 34 communicates with the through hole 37 through the ink receiving chamber 35.

  Further, as shown in FIG. 3, three second flow paths 38 communicating with the first flow paths 34 through the through holes 37 are formed in a groove shape on the back surface 30 b of the base material 30. Here, the through-hole 37 is orthogonal to the paper surface in FIG. 2, which is different from the direction in which the ink flows in the first flow path 34 with respect to the ink receiving chamber 35 (direction parallel to the paper surface in FIG. 2). Direction) to connect the ink.

  On the other hand, a plurality (three in the present embodiment) of choke valves 40 are formed in parallel along the longitudinal direction of the extending portion 25 b in the extending portion 25 b of the base material 30. In other words, at three locations on the surface 30 a of the extended portion 25 b of the base material 30, an elongated ink introduction path 41 and a substantially circular ink receiving chamber 42 communicating with the ink introduction path 41 are recessed. . The inner wall surface 44 of the ink receiving chamber 42 is formed so as to draw an involute curve, and the ink introduction path 41 is formed so as to continuously draw the involute curve similarly to the inner wall surface 44 of the ink receiving chamber 42. ing. Then, the terminal end (downstream end) of each second flow path 38 formed on the back surface 30b of the base material 30 opens at the inner surface of the base end side (the side opposite to the ink receiving chamber 42) of the ink introduction path 41. The opening portion serves as a supply port 45 for supplying ink to the ink introduction path 41. The ink introduction path 41 gradually tapers from the base end side (upstream side portion) where the supply port 45 is formed toward the downstream side portion where the connection port 46 which is a connection portion with the ink receiving chamber 42 is formed. It is formed to become.

  FIG. 5 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 5, the inner bottom surface 47 of the ink receiving chamber 42 is formed flat. A convex portion 48 is formed at a substantially central position of the inner bottom surface 47 of the ink receiving chamber 42. A discharge port 49 (for discharging ink from the ink receiving chamber 42) is formed at the tip of the convex portion 48. A liquid outlet portion is formed in the opening. And the 3rd flow path 51 which makes this discharge port 49 an upstream end is formed in the back surface 30b of the base material 30 at groove shape. The third flow path 51 extends toward the distal end (right end in FIG. 3) of the extension portion 25 b and communicates with the connection port 25 c with the ink supply tube 22. Here, the discharge port 49 is different from a direction (a direction perpendicular to the paper surface in FIG. 2) different from the direction of the ink flow (the direction parallel to the paper surface in FIG. 2) flowing through the ink introduction path 41 with respect to the ink receiving chamber 42. ) To lead out ink.

  The first flow paths 34, the ink receiving chambers 35, the ink introduction passages 41 and the ink receiving chambers 42 in the choke valve 40 formed on the surface 30 a of the base material 30 are flexible on the surface 30 a of the base material 30. The film 31 as the valve body is sealed by heat welding. Similarly, in each of the second flow path 38 and the third flow path 51 formed on the back surface 30b of the base material 30, a film 31 as a flexible valve body is also thermally welded to the back surface 30b of the base material 30. Is sealed.

  As shown in FIG. 5, in the choke valve 40, the film 31 (specifically, the flexible portion 31a corresponding to the ink receiving chamber 42) is thermally welded, so that the sealed ink receiving chamber 42 is formed. It is enclosed as a pressure chamber. That is, the film 31 is thermally welded to portions other than the ink introduction path 41, the ink receiving chamber 42, and the convex portion 48 on the surface 30 a of the base material 30. The film 31 has a valve-open state in which the flexible portion 31a corresponding to the ink receiving chamber 42 opens both the supply port 45 and the discharge port 49 by the ink supply pressure in the ink receiving chamber 42 (pressure chamber). It is designed to be flexible between a closed state in which the discharge port 49 is closed.

  In the choke valve 40 described in detail above, the inner bottom surface 47 of the ink receiving chamber 42 and the film 31 are parallel to each other along the vertical direction, and the discharge port 49 is formed through the substrate 30 along the horizontal direction. It is configured as a so-called vertical type valve device.

Now, the operation of the printer 10 will be described by focusing on the operation of the first and second flow path forming bodies 25 and 26 as the liquid circulation device.
First, when ink is supplied from the ink cartridge 21 to the recording head 15 for printing, the pressure pumps 23 and 24 are driven, and the air inserted into the through holes 32 from the pressure pumps 23 and 24. The ink pack in the ink cartridge 21 that has been supplied with pressurized air through the supply tube is deformed so as to be crushed. Then, the ink stored in the ink cartridge 21 is pressure-fed to the corresponding flow path forming bodies 25 and 26. In addition, in the following description, since the effect | action in the 1st and 2nd flow path formation bodies 25 and 26 is the same, the 1st flow path formation body 25 is demonstrated for convenience of explanation.

  The ink in the ink cartridge 21 is pressure-fed from the communication hole 33 to the first flow path 34 of the first flow path forming body 25 via an ink needle (not shown) provided in the cartridge holder 18. The ink sequentially flows through the first flow path 34 to the downstream side, and flows into the ink receiving chamber 35 through the terminal portion 34 a of the first flow path 34. At this time, since the end portion 34a of the first flow path 34 is connected to the ink receiving chamber 35 in the tangential direction of the inner wall surface 36 of the ink receiving chamber 35, the inside of the first flow path 34 (upper end portion 34a). The ink smoothly flows into the ink receiving chamber 35.

  The ink that has flowed into the ink receiving chamber 35 flows in a circular manner in the ink receiving chamber 35 along the inner wall surface 36 formed so as to form a circular arc shape in the ink receiving chamber 35. It flows from a through hole 37 formed at the center of the chamber 35 into a second flow path 38 formed on the back surface 30b. That is, the flow of ink from the first flow path 34 to the through hole 37 is promoted by the inner wall surface 36 of the ink receiving chamber 35 formed in a circular shape, and minute bubbles mixed in the flow path are particularly affected by the inner wall surface. The ink is discharged from the through hole 37 as the ink flows without staying in the vicinity of 36.

  Next, the ink in the second flow path 38 flows into the ink introduction path 41 from the supply port 45 in the choke valve 40. The ink flows through the ink introduction path 41 to the downstream side (ink receiving chamber 42 side). At this time, the ink introduction path 41 is gradually tapered from the upstream portion on the base end side where the supply port 45 is formed toward the downstream portion where the connection port 46 which is a connection portion with the ink receiving chamber 42 is formed. Thus, the flow rate of the ink at the connection portion (connection port 46) is increased, and the ink is urged into the ink receiving chamber 42 with a strong force. Further, since the ink introduction path 41 is formed in an involute curve shape continuous with the inner wall surface 44 of the ink receiving chamber 42, the ink is smoothly introduced from the ink introducing path 41 to the ink receiving chamber 42.

  The ink that has flowed into the ink receiving chamber 42 at a sufficient flow velocity gradually moves along the inner wall surface 44 of the ink receiving chamber 42 formed so as to draw an involute curve (the discharge port 42). 49) in a spiral shape (see arrows in FIG. 2). That is, the flow of ink from the ink introduction path 41 to the discharge port 49 is promoted by the inner wall surface 44 of the ink receiving chamber 42 formed so as to draw an involute curve. Further, since the inner wall surface 44 of the ink receiving chamber 42 is formed in a smooth curved shape, minute bubbles mixed in the ink are discharged from the discharge port 49 along with the circulation of the ink without particularly staying in the vicinity of the inner wall surface 44. Will be. Then, the ink discharged from the discharge port 49 flows through the corresponding ink flow path of the ink supply tube 22 and is supplied to the sub tank 16 on the carriage 14 provided with the recording head 15.

According to the embodiment described above, the following effects can be obtained.
(1) In the above embodiment, the inner wall surface 36 of the ink receiving chamber 35 is formed in a circular shape (circular arc), and from the tangential direction of the inner wall surface 36 (from the end portion 34a of the first flow path 34). ) Ink is introduced into the ink receiving chamber 35. As a result, the flow of ink in the portion where the flow direction of the ink is changed from the first flow path 34 to the second flow path 38 (that is, the ink receiving chamber 35) is promoted. It can be easily led out to the second flow path 38 side without staying at a location (specifically, in the vicinity of the inner wall surface 36 of the ink receiving chamber 35). That is, it is possible to efficiently discharge bubbles that tend to stay upward in the vertical direction and prevent printing defects such as missing dots.

  (2) In the above embodiment, in the choke valve 40, the inner wall surface 44 of the ink receiving chamber 42 is formed in an involute curve shape continuous from the ink introducing passage 41. Through this, it is possible to promote the circulation of the ink to the discharge port 49. That is, by the same effect as the above effect (1), minute bubbles mixed in the ink flow path are easily led to the third flow path 51 side without staying in the vicinity of the inner wall surface 44, thereby preventing printing defects. be able to. In particular, when the choke valve 40 is installed vertically, bubbles tend to stay above the ink receiving chamber 42 in the vertical direction. However, according to the above-described embodiment, the bubbles can be efficiently discharged even in such a vertical installation. Can do.

  (3) In the above embodiment, the ink introduction path 41 is directed from the upstream side portion on the base end side where the supply port 45 is formed to the downstream side portion where the connection port 46 which is a connection portion with the ink receiving chamber 42 is formed. It is formed so as to taper gradually. For this reason, the flow rate of ink at the connection portion (connection port 46) is increased, and the ink can be pumped vigorously into the ink receiving chamber 42. That is, according to this configuration, the ink can be smoothly circulated in the ink receiving chamber 42 in a more preferable manner, and the bubbles in the ink receiving chamber 42 can be efficiently discharged.

  (4) In the above embodiment, the inner bottom surface 47 of the ink receiving chamber 42 in the choke valve 40 is formed flat. For this reason, for example, compared with a choke valve in which the inner wall surface of the ink receiving chamber is shallow and the cross-sectional shape that gradually becomes deeper toward the center is tapered, the ink as the pressure chamber A sufficient volume of the receiving chamber 42 can be secured. Therefore, in the printer 10, a suitable flow state of ink can be maintained, and the responsiveness of the choke valve 40 as a valve device can be improved. In addition, forming the inner bottom surface in a tapered shape as described above is a preferable form for moving the bubbles from the inner wall surface 44 of the ink receiving chamber 42 toward the central discharge port 49 and discharging them. In this embodiment, the discharge is sufficiently taken into consideration by the shape of the inner wall surface 44 of the ink receiving chamber 42 and the mode of ink distribution from the tangential direction. For this reason, the inner bottom surface 47 can be flattened, and both the discharge of bubbles and the responsiveness of the choke valve 40 are improved.

The above embodiment may be changed to another embodiment (another example) as follows.
In the above embodiment, the ink introduction path 41 does not have to be tapered from the base end side where the supply port 45 is formed toward the connection portion (connection port 46) with the ink receiving chamber 42.

-The convex part 48 in the choke valve 40 of the said embodiment does not need to be formed. In this case, the discharge port 49 may be directly formed in the inner bottom surface 47.
In the above embodiment, the through hole 37 and the discharge port 49 as the liquid lead-out portion may be formed at a location other than the center position of each ink receiving chamber 35, 42.

  In the above embodiment, the inner bottom surface 47 of the ink receiving chamber 42 may be formed such that the vicinity of the inner wall surface of the ink receiving chamber 42 is shallow, and the cross-sectional shape that gradually becomes deeper toward the center portion is tapered. According to this configuration, the air bubbles staying in the vicinity of the inner wall surface can be gradually moved to the discharge port 49 side and discharged by the action of the film 31 bent toward the inner bottom surface 47 side.

  In the above embodiment, the ink introduction path 41 may not have a shape that draws an involute curve. If only the inner wall surface 44 of the ink receiving chamber 42 is formed so as to draw an involute curve, the flow of ink in the ink receiving chamber 42 can be promoted, and bubbles can be discharged efficiently.

  The ink receiving chambers 35 and 42 of the above embodiment may be formed such that the inner wall surfaces 36 and 44 have a substantially arc shape other than a circular shape or an involute curve shape. Even in this case, the ink circulated in the ink receiving chambers 35 and 42 from the tangential direction of the inner wall surface can be smoothly circulated in each ink receiving chamber by the inner wall surface formed in a substantially arc shape.

  In the above embodiment, the inner wall surface 36 that promotes the flow of ink in only one of the configuration in which the flow path direction is changed from the first flow path 34 to the second flow path 38 and the choke valve 40, The ink receiving chambers 35 and 42 having the shape of 44 may be configured.

  In the above embodiment, the liquid distribution device of the present invention is embodied in the flow path forming bodies 25 and 26, but may be embodied in other fluid flow paths. For example, a valve device provided in the middle of the ink discharge tube (liquid flow path) 28 in the cleaning mechanism 20 may be embodied as a valve device having the same configuration as the choke valve 40 in the above embodiment. In addition, the present invention can be applied to a corner portion or the like of each liquid channel in which bubbles tend to remain because the ink channel direction is changed.

In the above embodiment, the flexible valve body may be constituted by a rubber sheet or the like instead of the film 31.
In the above-described embodiment, the embodiment is embodied in the off-carriage type ink jet printer 10, but the present invention is not limited thereto, and in the on-carriage type ink jet printer, a valve device provided in the middle of the ink discharge tube (liquid flow path). It may be embodied in.

  In the above embodiment, the printer 10 that ejects ink has been described as the liquid ejecting apparatus, but other liquid ejecting apparatuses may be used. For example, printing apparatuses including fax machines, copiers, etc., liquid ejecting apparatuses that eject liquids such as electrode materials and coloring materials used in the production of liquid crystal displays, EL displays, and surface-emitting displays, and bio-organic materials used in biochip manufacturing It may be a liquid ejecting apparatus for ejecting a liquid or a sample ejecting apparatus as a precision pipette. Also, the liquid is not limited to ink, and may be applied to other liquids.

1 is a perspective view of a main part of an ink jet printer according to an embodiment. The front view of a flow-path formation body. The back view of a flow-path formation body. The figure which expands and shows the terminal vicinity vicinity of a 1st flow path. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. The longitudinal cross-sectional view which shows schematic structure of the conventional choke valve.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Inkjet printer as a liquid ejecting apparatus, 15 ... Recording head as a liquid ejecting head, 25, 26 ... Flow path forming body as a liquid distribution apparatus, 34 ... Liquid flow path, First flow path as a liquid introduction part 34a ... the end of the first channel, 35, 42 ... the ink receiving chamber as the liquid receiving chamber, 36, 44 ... the inner wall surface, 37 ... the through hole as the liquid outlet, 38 ... the second as the liquid channel. Flow path, 40 ... Choke valve (valve device), 41 ... Ink introduction path as liquid introduction part, 45 ... Supply port, 46 ... Connection port, 47 ... Inner bottom surface, 49 ... Discharge port as liquid outlet part, 51 ... A third channel as a liquid channel.

Claims (3)

A liquid receiving chamber which is provided in the middle of the liquid flow path and constitutes a pressure chamber of the choke valve, a liquid introducing portion for introducing the liquid into the liquid receiving chamber from the upstream side of the liquid flow path, and a liquid receiving chamber A liquid circulation device comprising a liquid outlet portion for discharging the liquid downstream of the liquid flow path;
The liquid receiving chamber is formed so that its inner wall surface has a substantially arc shape that draws an involute curve in a cross-sectional shape along the vertical direction of the liquid receiving chamber ,
The liquid introducing portion is formed so as to continuously draw an involute curve on the inner wall surface of the liquid receiving chamber, and gradually increases from the upstream side portion toward the downstream side portion serving as a connection portion with the liquid receiving chamber. Formed to be tapered and connected to the liquid receiving chamber so as to introduce the liquid into the upper portion of the liquid receiving chamber from the tangential direction of the inner wall surface of the liquid receiving chamber ;
The liquid lead-out portion is connected to the liquid receiving chamber so as to lead out the liquid from a substantially central position in the vertical direction of the liquid receiving chamber, and the liquid introduced from the liquid introducing portion into the liquid receiving chamber A liquid circulation device configured to be led out from the liquid lead-out portion after flowing in a circular shape from above to below along the inner wall surface of the liquid receiving chamber. The liquid circulation device according to claim 1 , wherein the liquid receiving chamber has a flat inner bottom surface. A liquid ejecting head that ejects a liquid, and a liquid distribution device according to claim 1 or 2, a liquid-jet apparatus characterized by the liquid deriving unit in the liquid flow device is connected to the liquid ejecting head.

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